Nothing neo can be reactionary. Reactionaries are defined as an old order attempting to resist a rising new order. Christianity is/was the old order in our time and many Christians have reactionary leanings.

Since we would end up with mostly males, all men under 1.8m must go.

Blitzkrieg is right. No reason a little bit of robotics and a great deal of smart system design can't fill in the remaing gaps. Sorry, but most of the human race is unnecessary, costly in fact.

Hippocrates's school of medicine would not have been built by those who attended it. Pythagoras and his followers/associates would have had far more difficulty creating their theories while lifting stones for a building.

We value the learning that came about, not the buildings that were created. The learning lasted, is still put to use and expanded upon. Many of the buildings did not last and probably none are put to use as intended by those who commissioned the work. These decay into corruption and dust. Learning, like living things, lives on, grows and assuming appropriately supportive minds continue to exist, may flourish indefinitely.

The reason why such large numbers of the lower class existed particularly in those civilizations is because they all enjoy frivolous things. The pyramids, the Parthenon, the coliseum. All these structures of which those civilizations built many of and many similar to take a great deal of skill, labor and time to create. If you wanted a society of the few and elite you could not have such beautiful architecture, roads and buildings would be small and undecorated.

I'm not so sure these material luxuries highlight the apex of mankind's worthiness as a species. Birds, bugs and rodents are also exquisite architects. But they never uncover the mysteries of the universe, decode its intangible mathematics, predict its Forms, comprehend its logic, structure and cycles.

That's really why we exist, not to make physical luxuries - the output of knowing, not the foundation of understanding - that decay and are forgotten in time. For all our understanding up until this time, what output are we producing for it today?

I'm unclear what our vastly more complex modern society has done to make humanity a more worthwhile species than what the Greeks produced. I'm also noting the sensible polis communities they had at one point, which to my knowledge did not need to rely on a servant class in order to prosper.

Its easy to say that smart people should control government and the idiotic should have little power in themselves and i do agree with this, But it is when we actually start to make some sort of plan or present a plan of our own that we must elaborate on.

We have governments in order to manage the idiots. Governments serve no other need.

Who is stupid, what characteristics befall one who is stupid (and it would be best to avoid the tautology here) and why these are unfavorable. All these things need to be explained when someone suggests to cull the population starting at the bottom.

This is similar to the trouble with having a democracy with everyone voting, except we're instead discussing everyone integrated into the same civilization, or inhabiting the same planet for that matter.

The menial but necessary tasks that make up most of human existence are best done by those too stupid to be aware of their tedium.

We have mostly menial necessary tasks in society because of its poor design. High IQ people not wasting their talent managing the low IQ pool and designing society around the needs of a large low IQ pool would create a more elegant civilization.

Take automobiles for one example. The typical auto factory worker, gas station attendant, parts store cashier, service mechanic or salesman is probably below 120. But, we use automobiles because we have sprawling suburbs, which is a design defect. Efficient, simplified human habitats would eliminate the need for millions of autos and consequently, millions of sub 120s imbedded within the support infrastructure.